The invention relates to a dental appliance and more particularly to a device for collecting solid debris, for preventing debris from falling into the throat (oral pharynx) even when the patient is placed in a supine position, and removing liquid from the mouth of the patient during the conduct of dental operations therein.
In the past, saliva pumps (water pumps) have been used for removing liquid from the mouth of the patient during the conduct of dental operations. These pumps were perfected in the late 1900's and have for many years been a part of the dental operatory unit. In recent years a far more efficient system, the "high velocity vacuum" (an air pump) has been introduced to the dental profession. Although this system is highly efficient, it has several major drawbacks. First of all, the long life dependable system is very expensive. Secondly, the system is objectionable unless the air pump can be placed outside the confines of the dental office since it is very noisy and many medicaldental buildings do not lend themselves to this type of installation. Thirdly, until the advent of the Erickson Vac-Ejector described in U.S. Pat. No. 3,090,122, the use of high speed vacuum for evacuation required the service of a full time chairside assistant to hold the aspirator pipes. As a consequence of the three reasons recited above, only a relatively small percentage of dental operatories are equipped with a high velocity vacuum system and some of these are not in use, or are frequently not used because of noise, lack of help or mechanical failure.
By contrast, virtually every dental operatory in the world is equipped with a saliva pump. Even in the case of most modern and recently constructed dental facilities with custom made units, a saliva ejector line is present, connected to either a water or air pump.
The saliva pump with its attached saliva ejector is a very inefficient device. It is present in almost every operatory since it normally comes as part of the equipment at very little added cost and because it is better than nothing. The saliva pump is inefficient for dental evacuation because it moves only a relatively small volume of air or liquid per unit of time, as contrasted with the air pump which uses a great volume of air to sweep up liquids which are near any orifice of the system's oral appliance or aspirator pipe.
Also in the case of the saliva pump, any or all orifices to the system's saliva ejector must be immersed in the liquid to be evacuated. If air can enter the system through any orifice, only air will be evacuated. If the orifice to the saliva ejector (where only one exists) is occluded, a very high vacuum is created which results in severe injury to tissues if tissue take up is the cause of occlusion. Consequently, for almost a hundred years, saliva ejectors to be used with the saliva pump have been designed with initial considerations toward eliminating tissue injury by using multiple orifices, rubber tips, slots for air relief, etc. Further progress was made by attempts to keep the tongue out of the area of operation by adding a tongue blade, curls of plastic tubing, and the like, all of which were helpful in improving a bad situation. A major drawback to these prior systems, however, was that evacuation was only partial and that the patient needed to be seated in a nearly upright position. When it came to the point of maintaining an absolutely dry field for placement of filling materials, fluoride treatments, plastic sealants and the like, the operator had to resort to using cotton rolls, gauze sponges, or the like.
Attempts have been made to devise an instrument which would overcome or compensate for the deficiencies of the saliva pump. The inventor himself began working on the problem in the early 1950's. His first solution was a device disclosed in U.S. Pat. No. 2,937,445 which unfortunately was limited in its function and subject to the same failures as were all the contemporary and earlier devices designed to be used with the saliva pump. In the late 1960's the inventor again turned his attention to the task of trying to create an appliance which would make the saliva pump a truly viable evacuating system. The results of these efforts is disclosed in U.S. Pat. No. 3,924,333. This dental appliance, although having merit, suffers from a design that is too complex, and it is subject to the many deficiencies all appliances used with the saliva pump have experienced to date.
The basic problem that all the inventors have been tackling since the saliva pump was "perfected" has been the removal of saliva. However, saliva is generated by all healthy humans. It is necessary for the health and comfort of all the tissues, hard and soft, of the oral cavity and pharynx. It has been the advent of the high speed drill and the washed field technique which relies on copious amounts of coolant and wash water to be introduced into the area that is being operated on, that has created a problem. Not only does the liquid and the solid debris splash and spray about on the sensitive tissue of the soft palate and oral pharynx, they join whatever saliva the patient generates to form an unconfined "stew" that is spread all over the oral cavity. When the patient is reclined the stew gravitates into the patient's throat. The present day saliva ejector is impotent to prevent this.
It is an object of the invention to provide a dental appliance having positive means for forming a reservoir in the patient's mouth for collection of all the coolant and wash water and for directing these liquids to the evacuating orifice of the saliva ejector.
It is also an object of the invention to provide a dental appliance that would allow the patient to swallow a portion of his saliva only, thus allowing the patient to remain more comfortable as a result of saliva keeping lubricated and moist the tissues of the throat.
It is a further object of the invention to provide a dental appliance having a positive structure to control the tongue whereby it is confined to a level below and apart from the lingual surfaces of the teeth that are to be maintained dry during operations requiring the various quadrants of the mouth to be absolutely dry.
It is a further object of the invention to provide a dental appliance having positive means for the collection of induced liquids by utilization of portions of the natural anatomy of the oral cavity never before considered in design.
It is an additional object of the invention to provide a dental appliance which does not allow the passage of the liquid and solid debris into the throat.
It is also a further object of the invention to provide a dental appliance with structure for retaining the collector membrane which requires no special adhesive, clamps, connectors or the like.
It is an additional object of the invention to provide a dental appliance having structure for holding the membrane in the proper relation with the anatomical tissues which it contacts to form a reservoir for the collection of fluids and saliva that are generated.
It is an additional object of the invention to provide a dental appliance having an extension of a single evacuation bore so that the connecting tube from the saliva pump or other vacuum source does not come in contact with the oral tissues of the patient.
It is an additional object of the invention to provide a dental appliance having a tongue guard that can be utilized without a change in its assembly so that it can be used either from the right side or the left side of the patient to isolate and evacuate slightly more than one half of the teeth of either the right or the left upper and lower arches.
It is also a further object of the invention to provide a dental appliance whose cost makes it acceptable as a disposable item after being used by only one patient.